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