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