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