The "Alignment" setting for labels refers to the alignment of text inside the label box. It does not refer to the placement inside the node box. For that, you need to set "Placement" to "Internal: Left", "Internal: Topleft", or "Internal: Bottomleft".
To see the effect of "Alignment" you need to create a label with multiple lines of text (and a non-transparent border to visualize the label box):
Corresponding GraphML.