Realistically, you can't.

You can do a print screen with the codes displayed.

You can (1) widen your margins enough to handle the extra characters.
(2) do a replace that looks for every formatting character that you want to
show and replaces it with that character plus a symbol representing that
character.

This will come close, but will not be perfect because things will not wrap
in the same place and sometimes the tab symbol will move the text enough to
go to the next tab stop.

I think one of the MVPs, perhaps Suzanne Barnhill, has a macro that does the
replacing I describe. But I don't remember how to locate it. In the
meantime, take a look at
http://word.mvps.org/faqs/general/FindingSpecialCharacters.htm
for a start on doing this yourself.

Hope this helps.

I found the utility. It adds a command to your formatting menu "Toggle
Non-Printing Visible" that lets you create an approximation of the
non-printing characters. (It is called NonPrintingApproximation.dot). It
replaces the paragraph mark, tab mark, and space with appropriate
characters. I downloaded the utility from http://www.indelibleink.com. I
don't have a link to the utility itself.