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