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