If you are using a template file like Blank for the message body you can open up this page to customize your receipt. By default these template pages normally just loop over the posted data so it will use the name of the element for it's label.
If you want to have full control over the values and how they are displayed you can go to Bindings > Form Data and select the confirm page to get the data. This will give you all of the form bindings in the bindings panel. You can then create your own labels and drag and drop the values onto the message wherever you would like to see them.