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)(17,19)(18,22)(20,21)(23,24)(25,26,31,34)(27,29,33,30)(28,35,38,39)(32,37,40,36)(1,3,4,8)(2,5,6,7)(9,11)(10,14)(12,18)(13,19)(15,22)(16,17)(20,23)(21,24)(25,27)(26,29)(28,32)(30,34)(31,33)(35,37)(36,39)(38,40)(9,10)(11,17,19,14)(12,20)(13,16)(15,21)(18,22,24,23)(25,28,30,37,31,38,29,36)(26,32,33,39,34,40,27,35)(2,6)(5,7)(9,12,13,21)(10,15,16,20)(11,18,19,24)(14,22,17,23)(25,29,31,30)(26,33,34,27)(28,36,38,37)(32,39,40,35)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.