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