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