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