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