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