Requires the installation of blueutil, available via Mac brew, and assumes a symlink or other link to blueutil available at:
/usr/local/bin/blueutil
If you have brew installed, use the command:
brew install blueutil
If not, install blueutil on your own, or install brew first.
http://midknightgallery.com/storage/workflows/Toggle_Bluetooth.alfredworkflow
Keyword for bringing up the toggle is "bluetooth"