One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,6)(7,15)(8,11)(9,13)(10,14)(12,18)(16,20)(17,19)(21,22)(23,26)(24,27)(25,28)(29,32)(30,35)(31,33)(34,36) involution — undirected(2,4)(6,11)(7,16)(8,10)(13,14)(17,18)(19,20)(21,23)(22,26)(24,31)(25,30)(27,33)(28,35)(29,34)(32,36) involution — undirected(5,7,9,18)(6,12,13,15)(8,16,10,17)(11,19,14,20)(22,27)(24,32)(26,33)(28,29)(31,36)(34,35)(6,13)(11,14)(12,15)(19,20)(22,28)(23,30)(27,29)(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.