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