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