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