I have tested this lightly, and Graph::Easy seems to work - it should meet your requirements. It can "Render graphs as ASCII, HTML, SVG or Graphviz".

From the docs:

 use Graph::Easy;
        
        my $graph = Graph::Easy->new();

       $graph->add_edge_once ('Bonn', 'Berlin');

        print $graph->as_ascii( );

        # prints:

        # +------+     +--------+
        # | Bonn | --> | Berlin |
        # +------+     +--------+
[download]

There is a tutorial,and samples, at the author's website.