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