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)(21,22)(23,31)(24,28)(25,29)(26,30)(27,33)(32,35)(34,36) involution — undirected(5,7)(6,11)(8,15)(9,18)(10,16)(12,19)(13,14)(17,20)(21,23,25,33)(22,27,29,31)(24,35,30,36)(26,32,28,34)(1,2,3,4)(21,24)(22,28)(23,27)(25,30)(26,29)(31,33)(32,35)(34,36)(5,8,10,9)(6,12,13,17)(7,15,16,18)(11,19,14,20)(22,29)(24,30)(27,31)(35,36)(5,9,10,8)(6,12,13,17)(7,15,16,18)(11,20,14,19)(22,29)(23,32)(26,28)(27,35)(31,36)(33,34)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.