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