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