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