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