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