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