Here are two possible workarounds.
. , , , 1.
:
Table[Graph[{1 -> 2, 2 -> 3, 3 -> 1}, VertexSize -> 0.3,
VertexLabels -> Table[i ->
Placed["vertex" <> ToString[i], p], {i, 3}],
VertexShapeFunction -> "Square", PlotLabel -> p],
{p, {Left, Top, Right, Bottom, Center}}]
. [Edit: Center, , , , \n , , , .]
:
Graph[{1 -> 2, 2 -> 3, 3 -> 1}, VertexLabels -> Placed["Name", Tooltip]]
, .