You can create some great shapes from Google Drawings, but one thing you cannot do is overlapping Venn diagrams. Well enter Gliffy to save the day! Gliffy allows you to create all kinds of overlapping diagrams. Not only can you easily manipulate the shapes, but you can also move the words around easily. Either you can sign up for an account or you can have your students make their diagram and then take a screen shot of it and paste it into their Google Drive drawing (or dare I say Microsoft Word).
I found Gliffy on the slideshow below. Yes it is lot of slides. I'd recommend going through it quickly and stopping at the interesting ones and know that ones that I find interesting I will feature in the next few days as well. I found it on Google+ post from Eric Sheninger.