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