Persistent visual states for Toggle-as-a-button

From what I understand, the recommended way to create a button that functions as a toggle is to use something like:

 GUILayout.Toggle(pressed, "Toggle me !", "Button");

However, this basically leads to the creation of a button with an On-value-changed event listener. The button graphics still function as if in a button rather than a toggle. i.e., when I press the button and release, the button does not retain the "pressed" graphic state. How can this be accomplished correctly?

Or alternatively, what is the best way to create a Toggle-without-a-checkbox-which-looks-like-a-button in Unity 5?

Thank you! P.S. If anybody is aware of a detailed guide that will be useful in this matter, please link me to it.