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