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