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