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