if you installed the swtbot plugin/bundle via eclipse then you'll need an eclipse plugin project that depends on that bundle to hold your tests. Create a new plugin project and edit the manifest file to import the swtbot bundle.
You will then need a run configuration that will launch the application under test. I'm not sure how this can be achieved with a standalone maven project, but there's probably a way. If the project under test was an Eclipse application, you'd only need to right-click on your swtbot test and select run as swtbot test. I don't have an Eclipse with swtbot up and running atm so I can't give more detail, sry
[EDIT]
IMHO you should first try to test a dummy eclipse application. Put the plugin containing your test and the one containing your dummy app in your workspace, then run the test as described above. Once you have that running you should have a look at this post and the answer by the maintainer of SWTBot. A new instance of Eclipse will be launched with all UI contributions added by your dummy Eclipse application and the test will be run.
And have you already seen this similar post on SO? Sounds promising to me...