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