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