It's not really about singing the right tune, it's about being yourself and making sure you answer the questions with good solid examples of when you have demonstrated key competencies.
Make sure you listen and answer the question being asked instead of just firing off one of your prepared answers that doesn't quite fit. Don't be afraid to ask them to repeat the question.
Key competencies are pretty standard across consultancies at the grad level.
Know what motives you to work in consultancy and that company.
Demonstrate your ability to manage yourself and deal with uncertainty/ambiguous situations.
Demonstrate when you have sought feedback and looked to improve (think about what hasn't gone well for you and what you learnt from it.)
Demonstrate that you are goal oriented and driven to achieve results.
Demonstrate that you can work well with other team members, and have made use of the strengths of the people you know/worked with.
Be realistic if you have stock answers and everything is the best you will fail to convince and thus fall short of effective communication.
