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