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