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