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