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