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