One vertex per element, one color per generator, with an edge from x to x·s.
(2,5)(3,7)(10,14)(12,16)(19,23)(22,24)(26,30)(31,33)(32,36)(38,39) involution — undirected(2,5)(6,8)(10,14)(11,15)(18,21)(22,24)(25,26,29,30)(27,33,35,31)(28,32,37,36)(34,39,40,38)(1,2)(3,6)(4,5)(7,8)(9,10,13,14)(11,12,15,16)(17,18,20,21)(19,22,23,24)(25,26)(27,31)(28,36)(29,30)(32,37)(33,35)(34,39)(38,40)(1,2)(3,6)(4,5)(7,8)(9,11,13,15)(10,12,14,16)(25,27)(26,31)(28,34)(29,35)(30,33)(32,38)(36,39)(37,40)(1,3)(2,6)(4,7)(5,8)(9,12)(10,15)(11,14)(13,16)(17,19)(18,22)(20,23)(21,24)(25,28,29,37)(26,32,30,36)(27,34,35,40)(31,38,33,39)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.