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