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