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