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