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