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