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