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