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