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