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