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