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