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