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