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