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