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