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