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