Instructions:

1. Get TikZiT, a graphical editor for TikZ figures.
2. Download this TeX template as a ZIP file and unzip it somewhere.
3. Load the included .tikzstyles file by clicking the folder icon in the top-right corner of TikZiT.

...and off you go! Have a look at the .tex file to see how to set things up. If you have more questions, go to https://tikzit.github.io and scroll down!