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