If you saved the job before changing to print-to-file you can. Or if you printed it before, you can retrieve it from the job log (button at the top of the main window).
When you set up the print-to-file, you probably used a page size that is different from what you were using before. If you are already set up to print to a printer and you switch to print-to-file, there is a button to the right of the "Resolution" entry that says "Use current printer page size and PPI" and that will create a print-to-file page that matches what you are using so this resizing doesn't happen.
Mike