When using SQL database, there are different ways to show the flow of the system. In the bank you can use an ER to show its attributes. And for its operation uses a Diagram of Classes UML.
What better way to represent a NoSQL database for the end user, if there is any diagram I can use.
The key is not to confuse data structure with ways to model data structure. NoSQL databases come in various forms in terms of data structure, e.g. hierarchical, unstructured, semi-structerd and so on. It is feasible to model hierarchical structures (JSON, XML etc.) using Entity Relationship diagrams, UML Class Diagrams etc., but more difficult to model unstructured text or binary data this way. For unstructured data you might choose instead to model these as a document structures (i.e. document database pattern) using artefacts or objects in UML.
