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