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