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