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