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