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