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