entities = project.entity_set.all()

    # Set-up dictinary that will contains clusters of entities belonging to same

    # location.

    clusters = {}

    # Dictinoary for storing mapping between nodes and colours.

    node_colors = {}

    # Get distinct colours, one for each node/entity.

    colors = get_distinct_colors(entities.count())

        # Try to get the existing cluster based on location name.

        location = entity.location

        cluster_name = location.name.replace(" ", "_").lower()

        cluster = clusters.get(cluster_name, None)

        # Set-up a new cluster for location encountered for the first time.

        if cluster is None:

            cluster = pydot.Cluster(graph_name=cluster_name, label=location.name)

            clusters[cluster_name] = cluster

        # Fetch a colour that will be associated with the node/entity.

        node_colors[entity.id] = node_color.hex

        # Determine whether the node label should be black or white based on brightness of node colour.

        node_color_brightness = 1 - (node_color.rgb["r"] * 0.299 + node_color.rgb["g"] * 0.587 + node_color.rgb["b"] * 0.114)

        if node_color_brightness < 0.5:

            font_color = "black"

        else:

            font_color = "white"

        # Finally create the node, and add it to location cluster.

        node = pydot.Node(entity.name, style="filled", color=node_color.hex, fontcolor=font_color)