1. Calculate the coordinates of the points of intersection between the plane and the coordinate axes. For instance: The x-axis crosses the plane if y = 0 and z = 0, thus , etc.
2. Draw the 3 axes and the intersection points. You'll get a triangle which defines the plane in 3D. The sides of the triangle are the intersections between the given plane and the coordinate planes.
(Remark: I used isometric paper whose axes include an angle of 120°)