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)(27,33)(28,31)(29,32)(30,35)(34,40)(36,38)(37,39)(3,8)(5,7)(19,23)(21,24)(25,26,29,32)(27,33,35,30)(28,31,38,36)(34,40,37,39)(1,3)(2,5)(4,8)(6,7)(9,10,13,12)(11,14,15,16)(17,18)(19,21)(20,22)(23,24)(25,26)(27,30)(28,36)(29,32)(31,38)(33,35)(34,40)(37,39)(1,3)(2,5)(4,8)(6,7)(9,11,13,15)(10,14,12,16)(17,19)(18,21)(20,23)(22,24)(25,27,29,35)(26,30,32,33)(28,37,38,34)(31,40,36,39)(1,2)(3,5)(4,6)(7,8)(9,12,13,10)(11,16,15,14)(17,18)(19,21)(20,22)(23,24)(25,28,29,38)(26,31,32,36)(27,34,35,37)(30,39,33,40)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.