How to document sql query

For a Client of mine I'm documenting an existing database with a few tables and some queries.

For tables I'm using E-R Diagram to show tables and relationships. I'm doing that with DIA Diagram Editor.

How do I describe and visualize queries? There exist some sort of UML Object to do that?

So far, I've created a table with query name and a description of what it does and an example screenshot of data retrieved by the query itself. I'm doing that in Word.
I don't like the result of this work, there exist something more professional to do that?

I wouldn't install new software just know how database designers have to accomplish that task.

EDIT 1 As @Serg suggested I may use view and diagramm the view as an entity.

If I've understood something like:

What the client needs is to understand for each query where data come from.

EDIT 2 I'm doing something like the following:

Where driver_tabella_utenti is a TABLE
driver_imp_causali_preparazione is a QUERY
driver_query_riepilogo_prsp is a QUERY

I think that isn't bast practice! How can I visual design sql queries as I do with entities and relationships?