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