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