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