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