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