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