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