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