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