I have created a prototype bot which can answer question asked by user in natural language and translate it to SQL fetch data from database and display it back to user. Now, based on the data i got from database I want to convert it into graphs (eg: Bar, pie, etc) and show graphs to user.
In a custom action, you could produce the graph as a png or jpg, push it somewhere that is accessible by your bot UI and then reference the image in the bot response.