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