text: 
  import networkx as nx
  from matplotlib import pyplot as plt
  
  def graphviz(graph, edgecolor='grey', nodecolor='purple'):
    """
      Parameters
      ----------
      graph : graph object
          A graph object prepared by the graphprep function
      edgecolor : string
          Optional color selection for visualization
      nodecolor : string
          Optional color selection for visualization
      Returns
      -------
      A visualization of keywords.    
    """
  
    fig, ax = plt.subplots(figsize=(10, 8))
    pos = nx.spring_layout(graph, k=2)
    # Plot networks
    nx.draw_networkx(graph, pos,
                   font_size=16,
                   width=3,
                   edge_color=edgecolor,
                   node_color=nodecolor,
                   with_labels = False,
                   ax=ax)
    # Create offset labels
    for key, value in pos.items():
      x, y = value[0]+.135, value[1]+.045
      ax.text(x, y,
              s=key,
              bbox=dict(facecolor='red', alpha=0.25),
              horizontalalignment='center', fontsize=13)
      
    plt.show()
    
  