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