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