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