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