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