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