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