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