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