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