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