Do any of the links on this page
help? It seems like SoapUI is a GUI tool with limited ability to run from the command line, so even if you get it installed, you might have trouble accessing all functionality. I suppose if it absolutely must run in graphical mode, you'll have to set up X11 forwarding to the server (the "-X" or "-Y" flags to the ssh command), and then you'll be able to see the graphical display on your local Linux desktop.
If you need more help than this, it would be good to tell us which Linux distros you are running both on the server and your local workstation. Are there SoapUI packages for these distros available?