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