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