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