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