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