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