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