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