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