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