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