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