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