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