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