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