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