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