Through the pension trustees you should be able to ask for a prediction of what your pension would be worth per week from age 65, as well as what your pension would be worth now if you take it early (at 57).
Only you can work out what is best for you - you ask whether it makes much of a difference - yes, it sure does - but you ought to be able to see that from the values you get back. The pension value that you have accrued has to pay out for an extra 8 years worth. However if you need the money now, then I can understand you may feel it is worth drawing now. One only lives once.
You should actually be able to decide at ANY time between now and age 65 (or even later) that you want to start drawing your pension - ask the trustees about that - it isn't a question of only either now or at 65. So you could hold off until you feel you need the money.
Bear in mind that you will be able to draw your basic State Pension (currently worth about �90 per week) when you reach 65.
Also bear in mind that pensions are taxable, and that personal tax allowances increase sharply when one gets to age 65.