Hi Normen,
welcome to the Neo4j community!
I think that at the moment it is not possible to display the nodes as rectangles with a flexible width. The only shape that is allowed so far is circles. However, you can set the size of the circles and also the font size per distinct label of the nodes. How to: If you enter ":style" into your Neo4j browser, you will receive the current styling of your nodes. You can copy and paste the code in a text file and save it as a ".grass" file, change any of the options (e.g. diameter, font-size, etc.) that you want and upload it back in again (easiest way: go to "Favorites" (start on the upper left) and drag and drop the file).
What you always can do on top of that is to use a visualisation tool like yEd, Cytoscape or Gephi. You can export the graph from Neo4j and import it into any of the above tools. There you can do more styling. Also, the Bloom browser in Neo4j might help. But I am not sure, how much you can do with it.
I hope this helped you.
Regards,
Elena