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