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)(11,15,19,23)(12,17,22,21)(13,20,24,18)(1,3,6,5)(2,7,4,8)(9,11)(10,15)(12,18)(13,17)(14,19)(16,23)(20,22)(21,24)(25,26,30,31)(27,32,35,39)(28,36,38,29)(33,34,37,40)(1,2,6,4)(3,7,5,8)(10,16)(11,19)(17,21)(18,20)(26,31)(29,36)(32,39)(34,40)(1,3,6,5)(2,7,4,8)(9,12)(10,17)(11,20)(13,23)(14,22)(15,24)(16,21)(18,19)(25,27)(26,32)(28,37)(29,34)(30,35)(31,39)(33,38)(36,40)(1,4,6,2)(3,7,5,8)(9,13,14,24)(10,18,16,20)(11,21,19,17)(12,15,22,23)(25,28)(26,29)(27,33)(30,38)(31,36)(32,40)(34,39)(35,37)(1,5,6,3)(2,7,4,8)(9,11)(10,15)(12,20)(13,21)(14,19)(16,23)(17,24)(18,22)(25,29)(26,28)(27,34)(30,36)(31,38)(32,37)(33,39)(35,40)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.