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