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