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