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