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