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