Code

DiagramItemCollection items = new DiagramItemCollection();
				    DiagramNodeCollection nodes = diagram.Nodes;
				    DiagramLinkCollection links = diagram.Links;

				    foreach (DiagramNode node in nodes)
				    {
					  if (node.IncomingLinks.Count != 0 || node.OutgoingLinks.Count != 0)
					  {
						items.Add(node);
					  }
				    }

				    foreach (DiagramLink link in links)
				    {
					  items.Add(link);
				    }

				    TreeLayout treeLayout = new TreeLayout();
				    treeLayout.KeepGroupLayout = true;
				    treeLayout.Type = TreeLayoutType.Cascading;
				    treeLayout.Direction = TreeLayoutDirections.LeftToRight;
				    treeLayout.MultipleGraphsPlacement = MultipleGraphsPlacement.Horizontal;
				    treeLayout.Balance = TreeLayoutBalance.RightHeavy;
				    treeLayout.Arrange(diagram, items);

				    foreach (DiagramLink link in links)
				    {
					  link.Style = LinkStyle.Polyline;
					  link.Route();
					  link.SegmentCount = 1;
				    }