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