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