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