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)(11,15)(12,16)(13,17)(14,18)(19,22)(20,23)(21,24)(25,26,30,32)(27,34,35,40)(28,33,29,38)(31,36,39,37)(9,11,14,21)(10,15,18,24)(12,20,13,19)(16,23,17,22)(25,27,30,35)(26,31,32,39)(28,37,29,36)(33,40,38,34)(2,5)(6,8)(9,12,14,13)(10,16,18,17)(11,19,21,20)(15,22,24,23)(26,32)(27,35)(33,38)(36,37)(9,13,14,12)(10,17,18,16)(11,20,21,19)(15,23,24,22)(25,28,30,29)(26,33,32,38)(27,36,35,37)(31,34,39,40)(1,3,4,7)(2,6,5,8)(10,18)(15,24)(16,17)(22,23)(26,32)(31,39)(33,38)(34,40)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.