Auto Layout Positioning

Can anyone explain to me how the layout positioning works? The problem that I’m running into is when I click “Layout Now” or try to move the diagram with “Auto Layout” checked, the entire diagram moves to what seems an arbitrary position on the canvas.

For example, I’m trying to do a mind map type diagram with the central topic dead center on the canvas. With “auto layout” checked, it moves to the top left. I’d like to keep auto layout enabled, but have it centered.

Thanks beforehand.