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