Automator

0.　Automator -> Service -> Actions -> Utilities -> Run Shell Script Drag Run Shell Script to the blank on the right pane. Copy the following code into the input view.

STATUS=`defaults read com.apple.finder AppleShowAllFiles`
if [ $STATUS == YES ];
then
defaults write com.apple.finder AppleShowAllFiles NO
else
defaults write com.apple.finder AppleShowAllFiles YES
fi
killall Finder

1.　Set Service receives to no input and save as a new file like named ToggleInvisableFiles.
Automator
2.　System Preferences -> Keyboard -> Shortcuts -> Services -> ToggleInvisableFiles
Check it and double click the none and set a shortcut.

Script Editor

0.　Open Script Editor and copy the following code into it.

display dialog "Hide/Show the invisible files" buttons {"Show", "Hide"} with icon 2 with title "Switch to presentation mode" default button 1

set switch to button returned of result

if switch is "Hide" then
	do shell script "defaults write com.apple.finder AppleShowAllFiles -bool false;
KillAll Finder"

else
	do shell script "defaults write com.apple.finder AppleShowAllFiles -bool true;
KillAll Finder"

end if

1.　Save it as Application.
Script Editor