Different case books might be an option - but I believe the skillset of a strong interviewer makes a much bigger difference to convert an interviewer-led into a candidate-led case.
The basis nevertheless is knowing the case inside-out. Only if you do so, you can lead the case by the right questions here and there and let the candidate do the major work of driving the case forward. It takes experience but it's doable with some practice.
Hope that helps - if so, please be so kind and give it a thumbs-up with the green upvote button below!