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