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