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