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