I found that more often than not, the pathway diagram was not necessary to arrive at the correct answer. It may have been included as a distractor.
Key is to realize that this is a test that tries to get at how well you can think on your feet. You'll almost never have a question that involves intense calculations or a deep dive into a complex biological or chemical process.
My advice to you would be to try and see if you can find a way to "see around" the bulk of the pathway and get straight at what it is you're being questioned on. That may be best accomplished by simply stripping all the extraneous detail and focusing on products, reactants, and any intermediates, enzymes, etc. that may have something of critical importance to tell you, such as points in the pathway where the reaction can be diverted into another pathway etc.
That probably doesn't help much.