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