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)(11,18)(12,22)(13,16)(14,17)(15,20)(19,23)(21,24)(25,26)(27,33)(28,36)(29,31)(30,35)(32,38)(34,39)(37,40) involution — undirected(1,3,5,2)(4,7,8,6)(9,11,14,20)(10,15,17,18)(12,19,13,21)(16,23,22,24)(25,27,29,35)(26,30,31,33)(28,37,38,34)(32,40,36,39)(2,3)(6,7)(9,10)(11,15)(12,22)(13,16)(14,17)(18,20)(19,24)(21,23)(26,31)(28,38)(30,33)(34,37) involution — undirected(2,3)(6,7)(9,12,14,13)(10,16,17,22)(11,19,20,21)(15,23,18,24)(25,28,29,38)(26,32,31,36)(27,34,35,37)(30,39,33,40)(1,4,5,8)(2,6,3,7)(11,20)(15,18)(19,21)(23,24)(26,31)(27,35)(32,36)(34,37)(9,13,14,12)(10,16,17,22)(11,21,20,19)(15,23,18,24)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.