var graphicsPath = new GraphicsPath();
var points = new PointF[6];
points[0] = new PointF(tile.Points[0].X  -4, tile.Points[0].Y - 4);
points[1] = new PointF(tile.Points[1].X - 4, tile.Points[1].Y - 4);
points[2] = new PointF(tile.Points[2].X + 4, tile.Points[2].Y + 4);
points[3] = new PointF(tile.Points[3].X - 4, tile.Points[3].Y - 4);
points[4] = new PointF(tile.Points[4].X + 4, tile.Points[4].Y + 4);
points[5] = new PointF(tile.Points[5].X + 4, tile.Points[5].Y + 4);

graphicsPath.AddPolygon(points);

using (var pen = new Pen(Color.FromArgb(60, 60, 60), 3F))
    graphics.DrawPath(pen, graphicsPath);