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