I tried searching over the internet but could not find the right tool for the purpose, so if anyone could provide me a link to the tool which could parse and display a graph for
These are also questions that I have recently been curious about. And I think the answer from Stanislav has some good materials. Here were some materials that I found interesting:
Parsing:
Visualizing: Using the web vowl interface can be a great way to start to look at graphs and ontologies. Just start with the examples within the interface or drag and drop your own in. You can also edit the graphs with the tool very easily: http://www.visualdataweb.de/webvowl/
Protege, as a software, is not quite as visual but makes jumping into the details of viewing and manipulating rdf/owl quite light. And there are many basic examples and some good youtube videos. Jumping into using the reasoners available within the tool inspires - regarding what one can infer from the logic of the graph. I suggest the downloadable version: https://protege.stanford.edu/products.php