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