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