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