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