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