Installing Graphical User Interface (GUI) on Ubuntu is easy on Google Compute Engine VPS, or any VPS that let’s you have shell.

1. sudo apt update Update package lists.
2. sudo apt upgrade Upgrades all software.
3. sudo apt install lxqt Install LXQT or sudo apt install xfce4 xfce4-goodies Xfce desktop environment.
4. sudo apt install tigervnc-standalone-server Install Tiger VNC server. Or install your preferred VNC server.
5. vncserver This will start VNC server, provide your VNC password.
6. Tunnel port 5901 on your SSH client.
7. Connect to localhost:5901 on your preferred VNC client.

If you restarted the VPS, just type vncserver again to run VNC server.

If you want to resize the resolution of the desktop, type vncserver -geometry 1920x1080 replacing the resolution of your choice.