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