Sure you can!
Simply log into your account:
Click on 'YourUsername' on top of the page and press the 'Edit Profile' below your username and select the 'Preferences' tab; this is where you can update your preferences.
In the 'PRIVACY SETTINGS' section, select between Public, Only Friends, and Only Me for each sections of your profile.
Select Public, if you want it to be seen by everyone.
Select Only Friends, if you want to be seen by your friends only.
Select Only Me, if you want it open to be seen by you only.