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