Using Diagram Navigator and DB Objects pane
To navigate within the large diagram, use the Navigator tool available on the Navigation bar. It allows you to see the whole diagram in a reduced scale and to perform a number of operations over the diagram objects.
A mouse click in the Navigator area sets the center of the visible diagram area. The area currently visible in the main diagram area is outlined in a red bounding rectangle.
Select and drag an object to the diagram area or double-click it to add the object to the diagram.
Right-click an item within the list to call the context menu allowing you to:
find the selected object in the diagram (if the object is found, it will be highlighted in the diagram area);
add new objects to the diagram by Reverse engineering;
toggle objects representation mode: as a tree / as a list;
select the sorting mode applied to the objects in the list: by schema, name / by name, schema;
refresh the list.