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