This file use notugly.xsl: An XSL transform to pretty up the SVG output from Graphviz
See: www.hokstad.com/making-graphviz-output-pretty-with-xsl.html And: www.hokstad.com/making-graphviz-output-pretty-with-xsl-updated.html
By Vidar Hokstad and Ryan Shea; Contributions by Jonas Tingborn, Earl Cummings, Michael Kennedy (Graphviz 2.20.2 compatibility, bug fixes, testing, lots of gradients)