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