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