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