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