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