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)(17,20)(19,21)(22,23)(26,30)(28,35)(31,39)(32,36)(33,37)(38,40)(1,3,4,8)(2,5,6,7)(9,10)(11,16)(12,20)(13,15)(14,17)(18,23)(19,24)(21,22)(25,26,29,32)(27,31,34,40)(28,36,35,30)(33,38,37,39)(9,11,14,19)(10,16,17,24)(12,18,13,21)(15,22,20,23)(25,27,29,34)(26,31,32,40)(28,37,35,33)(30,38,36,39)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.