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