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