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