At one point I researched this. I was hoping to find a usable algorithm for automated diagramming but nothing exists, especially because of the Biblical English of the King James. I could create a sentence diagramming tool that lets you draw the connections manually, but I fear so few people would know how to use it -- I would have to learn sentence diagramming just to build the tool! -- that it wouldn't end up being a feasible thing to devote resources to.