One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,6,9,12)(7,13,15,20)(8,16,18,11)(10,17,19,14)(21,22,26,29)(23,31,34,36)(24,30,25,28)(27,33,35,32)(2,4)(21,23,26,34)(22,27,29,35)(24,33,25,32)(28,36,30,31)(5,7,9,15)(6,10,12,19)(8,17,18,14)(11,20,16,13)(22,28)(23,32)(24,25)(29,30)(31,36)(33,34)(22,29)(27,35)(28,30)(31,36) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.