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