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