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