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