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