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