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