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