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