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