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