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