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