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