help me please with drowing cylindrical spring !!!

I draw a spring by means of points, here so

GL.Begin(BeginMode.Points);

z = -100.0f;
for (angle = 0.0f; angle <= (2.0f * Math.PI) * spr; angle += 0.02)
{
x = radius * Math.Sin(angle)+left;
y = radius * Math.Cos(angle);

// Specify the point and move the Z value up a little
GL.Vertex3(x, y, z);
z += k;
}

Prompt how to make visualisation more beautifully so the spring would look as three-dimensional object

In advance thanks