Enjoy:

And papers by the artist on how to do it available at: http://bulatov.org/math/1107/

Update 16th Nov 12:

Comments and more links from PM2Ring:

That image is an example of a tessellation of the hyperbolic plane, in the
Poincaré disc projection. Escher learned about this stuff from H. S. M. Coxeter, probably the greatest geometer of the 20th
century.

Hyperbolic geometry is fun. And it’s much easier to create
regular & semi-regular tessellations in the hyperbolic plane than in the
Euclidean plane. John Baez discussed this topic a little while ago: Archimedean Tilings and Egyptian Fractions

Modern Dutch
graphic artist Jos Leys has done some nice work with hyperbolic tessellations:

In 2D: http://www.josleys.com/show_gallery.php?galid=262
In 3D: http://www.josleys.com/show_gallery.php?galid=342

Also see images by PM2Ring from and early post in this blog:

https://newtonexcelbach.wordpress.com/2008/06/30/pythagoras-penrose-and-pov-ray/