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