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