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