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