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