I\'m sure this has been answered but I cannot seem to find an answer.
I installed postgresql using Homebrew (brew install postgresql) which installed to /usr/local/Cella
System: MAC OS X 10.9.5
Now (ver. 9.4) this is under the dir called /Library/PostgreSQL
If you go there, open the folder named as the ver. of your PG and then go to the folder data you will find your DB. This is really a set of many-many-many different both binary and text files (most of those are named with long numbers like "92891" or so...
Note, to open the data folder you have to open its properties (right mouse click and select "Get info") and allow you to read this folder.
I wdn't suggest you to open the RW permissions if you aren't familiar with this as any smallest change can affect you whole DB which is would be sad..
Good luck!