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