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