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