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