Download CloudCompare. Drag your E57 file into the workspace. Use the Subsample tool to reduce point density (you don't need 200 million points for a 3DS mesh; reduce to 10 million).
You cannot 3D print a point cloud. A 3D printer needs a watertight mesh (STL). Converting to 3DS first (then to STL) allows you to repair geometry for physical fabrication. cxi to 3ds converter