First - welcome to the forum ! Glad you joined us!
OK, let's hope you're not talking London here (in which case, don't fall in love with this scooter!)
We can offer lots of ideas ....but I would also have a chat with your local scooter/motorcycle shop to see what is working for local owners. And, what has not!
Fixing your scooter to a solid object is best, with a locked cover over it, and some sort of motion alarm which can also page you.
Fancy "Piaggio", or worse - "Vespa" logo'd covers are the worst form of advertising a nice scooter beneath!
Lots of options...but for every one there is a guy who can defeat it in many cities.
Folks....give this person some more ideas, please.
Stig