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