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