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