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