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)(26,35)(28,33)(29,32)(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)(23,32)(30,35)(33,34)(2,4)(5,8,9,16)(6,11,12,18)(7,14,15,20)(10,17,13,19)(21,23)(22,28)(24,33)(25,32)(26,34)(27,36)(29,30)(31,35)(6,12)(10,13)(11,18)(17,19)(21,23)(22,29)(24,34)(25,32)(26,33)(27,31)(28,30)(35,36) involution — undirected(2,4)(7,15)(10,13)(14,20)(17,19)(21,24,25,26)(22,30,27,35)(23,33,32,34)(28,29,36,31)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.