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