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