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