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