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