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