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