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