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