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