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