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