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