edges = {1 \[DirectedEdge] 2, 1 \[DirectedEdge] 3, 2 \[DirectedEdge] 4, 2 \[DirectedEdge] 5,
              3 \[DirectedEdge] 6, 4 \[DirectedEdge] 7};
t = TreeGraph[edges, GraphStyle -> "VintageDiagram"]