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)(11,17)(12,19)(13,16)(14,15)(18,22)(20,21)(23,24)(25,26,32,30)(27,35,31,33)(28,34,29,38)(36,40,37,39)(1,3,5,7)(2,4,8,6)(9,11)(10,12)(13,21)(14,19)(15,17)(16,22)(18,23)(20,24)(25,27,32,31)(26,33,30,35)(28,36,29,37)(34,39,38,40)(1,3)(2,6)(4,8)(5,7)(10,15)(12,17)(16,24)(20,22)(25,28,32,29)(26,34,30,38)(27,36,31,37)(33,39,35,40)(1,3,5,7)(2,4,8,6)(9,12)(10,11)(13,22)(14,17)(15,19)(16,21)(18,24)(20,23)(25,29,32,28)(26,34,30,38)(27,37,31,36)(33,39,35,40)(1,3)(2,4)(5,7)(6,8)(9,13,14,23)(10,16,15,24)(11,18,19,21)(12,20,17,22)(25,30,32,26)(27,35,31,33)(28,38,29,34)(36,40,37,39)(1,4)(2,7)(3,8)(5,6)(9,11)(10,12)(13,21)(14,19)(15,17)(16,22)(18,23)(20,24)(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.