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