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