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