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