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