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