Siemens has a software package named "S7-smartlabel" to print labels for u. This program uses the symbolic information from your project. You can also download word templates from the support site to make them yourself. Search for the term "Labeling strips". If you can't find them, I'll post them here for you if you want.
You can print it on plain paper or order special labels you can use in a laser printer, but somehow I don't get a good quality with them.