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