I am working through a similar request. As the client already has automated some of the servies using soapUI (OS) my job is a little harder.
The OS version doesn't have the data source, data loop test steps to make a data driven test suite but there is always a work around.
You can use even the Open Source version to implement the three kinds of prevalent automation frameworks.
Action Driven framework - To apply this framework to soapUI you have to identify some common test steps in the setup, execution and validation of the service. Once identified, separate them out in a test suite and/or test cases and simply call the appropriate test suite/test step.
For example: I have a test step that validated that an order entry has been made in the db by the service so i'll create a test suite + test case and add a jdbc test step in there to search for order id based on the data i supply. The query will be parameterized. In the actual script, i'll execute the service and extract all the values necessary to run the db query. These values will be passed to the reusable test case using the run test test step.
A few things to remember, is if you have a large number of test cases/parameters and think that the service will need to be modified then put the parameters in an excel file and load them using groovy from the test suite setup script area.
You'll need scriptom api to work with excel or Jxl (a little more complicated implementation)
Data Driven framework, in this framework you basically identify different scenario that you want to run on the service and populate an excel with relevant data, then using groovy and scriptom or jexcel or jxl api loop through all the rows in the excel and execute the service with different data elements. This approach can be made as complex as you like and as simple as you want.
Keyword driven framework - this is probably the most complex frameworks of all to implement as it requres you to do a lot of planning, development and such. I am currently designing such a framework. I would have shared some details with you if there weren't confidentiality agreements in place.
I also understand that you are new to groovy, you should check out soapUI and groovy's site they have a lot of really good examples and remember there is always stackoverflow to answer your queries.
Let me know how you make out with this effort.