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