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