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