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