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