|Left: A 1979 drawing of a molecule man by American sculpture artist Jonathan Borofsky, holes representative of "molecules", a pre-cursor to the CPK model. Center: A 2005 CPK-stylized human molecule made by Canadian designer Shawn LaPaix for the University of British Columbia Art Gallery.  Right: A 2009 CPK-style human molecule representation made by American illustration artist Chris Gash for the New York Times. |
The letters CPK, is acronym of the surnames of chemists Robert Corey, Linus Pauling, and Walter Koltun, the inventors of the atom color coding system.
The first proto-type CPK human molecule depictions, so to speak, were the various hole-filled molecule man drawings and multi-story sculptures made American sculpture artist Jonathan Borofsky, first built in Los Angeles, in 1977 and 1978, originating because, as Borofsky says: 
“I was fascinated by this ‘molecule idea’, the simple fact that even though we appear to be quite solid, we are in fact composed of a molecular structure which in itself is mostly composed of water and air.”
|A CPK color coded ball and stick model of the amino acid proline (C5H9NO2).|
“Holes represent the molecules of all human beings coming together to create our existence”.
In theory, then, expanding or rather upgrading this "holes = molecules" model of a human, one could then extrapolate on this statement to make a CPK model of the atoms of a human, where each color represents the representative atoms that actually exist in people.
The first actual CPK human molecule was the 3-element nitrogen-oxygen-hydrogen made in 2005 by Canadian designer Shawn LaPaix for a poster “The Human Body in History” made for the University of British Columbia Art Gallery exhibit. 
In 2009, although it seems unaware of the previous work of LaPaix, American illustrator Chris Gash made 2-element nitrogen-oxygen (blue-red) CPK human molecule in the form of a running stick figure, as an illustration for a New York Times article on walking walking molecules. 
Full CPK depictions
See also: Human molecular orbital
One of the limitations of the CPK human molecule depiction is that humans, according to mass composition tables, and recent human molecular formula calculations, are made of 26 functional elements:
Human molecular formula
|Left: A "Mr. Carbon Atom" depiction of a human as type of valence shell carbon 12 atom with an type orbital electronegativity, by English biotechnologist Mark Janes. Right: A 26-element depiction of a human, which is in line with the known mass-composition based molecular formula of an average human.|
hence a 26-color coded representation of the human as a "molecular formula in action", in the prophetic 1919 word of American physician George Carey. The following, for example, would be the coloring scheme according to the popular molecular visualizer jmol:
Human molecular formula (color coded)
This would be a bit tricky to visually depict a human via this color coding scheme, but nevertheless possibly a good introductory hmolscience "homework assignment" would be a classroom poster project assigned to children as a way to learn both the philosophical implications of notion of the human as a reactive molecule and also to learn the general location and function of each element in the body.
To note, with the rise of quantum mechanics (1900-1932), the field of quantum chemistry needs to be taken into account, according to which topics such as electronegativity, spin, molecular orbital theory (human molecular orbital theory), chemical bonding, etc., need to be taken into account in the representation of a human molecule; such as shown below, namely a thermodynamic system / molecular bubbles depiction of a human molecular orbital for one human molecule, or rather one person's average daily trajectories and movements, viewed at a sped-up rate of viewing, according to human molecular orbital theory. 
One example of this approach is that taken by English biotechnologist Mark Janes and his "Mr. Carbon Atom" outfit, above left, wherein he uses part metaphor, part analogy, part extrapolation, and part scientific concept, to model a human as a type of evolved carbon atom.
1. CPK coloring – Wikipedia.
2. (a) shawnlapaix.com/#ubc (sample works) – ShawnLaPaix.com (dead site?).
(b) UBC – Wayback Machine.
3. (a) Gash, Chris (illustrator) and Fountain, Henry (writer). (2009). “Experiments Show that Molecules Can Walk, but Can They Dance?”, New York Times, Science, Apr 07.
(b) Chris Gash (about) – ChrisGash.com.
4. (a) Thims, Libb. (2007). Human Chemistry (Volume One) (ch. 9: Human Molecular Orbitals, pgs. 247-95. Morrisville, NC: LuLu.
(b) Thims, Libb. (2007). Human Chemistry (Volume Two). Morrisville, NC: LuLu.