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