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