It’s not a good idea to have a script for the viva. You can’t take such detailed notes in that you are effectively quoting pre-prepared responses. Besides, there are so many possible questions and variations of questions that to even attempt detailed notes would be foolish.
You can read in the viva though: your thesis is your companion in the exam, a faithful friend that has everything you need, right there for you to use.
- Need to check a quote? Look in your thesis.
- Got to find that exact number? Check your thesis.
- Examiners asking something specific? It may be worth peeking at a page or two.
You might not have all the answers; your thesis might not either. But to help you respond you can read, check, quote and find things. Scripted answers won’t help you in your viva, but reading your thesis will.