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