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