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