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