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