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