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