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