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