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