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