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