Hi Indranil
The Spring Integration visual editor is included with STS 2.7.2 and should appear whenever you open a Spring integration XML file. If you're seeing the standard XML editor when you open those files, try right-clicking the file and selecting Open With -> Spring Config Editor. The Spring Config Editor will automatically add both an integration tab and an integration-graph tab when you start working with Spring Integration schemas in the file.
Leo Dos Santos
Committer, SpringSource Tool Suite