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)(19,24)(20,22)(21,23)(25,26)(27,31)(28,30)(29,36)(32,38)(33,35)(34,40)(37,39)(1,3)(2,4)(5,6)(7,8)(9,11,14,16)(10,12,13,15)(17,18,21,23)(19,22,20,24)(26,28)(27,33)(32,36)(34,37)(2,7)(3,5)(10,13)(11,16)(17,19,21,20)(18,22,23,24)(25,27,30,33)(26,31,28,35)(29,37,38,34)(32,40,36,39)(1,4,6,8)(2,3,7,5)(9,12)(10,11)(13,16)(14,15)(17,20,21,19)(18,22,23,24)(25,28,30,26)(27,31,33,35)(29,36,38,32)(34,39,37,40)(1,5,6,3)(2,8,7,4)(9,13,14,10)(11,12,16,15)(17,18)(19,24)(20,22)(21,23)(25,29)(26,32)(27,34)(28,36)(30,38)(31,39)(33,37)(35,40)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.