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