I'm not sure if you find a ready to use demo, but you can try to move one of you existing process to create a PoC.
What is worth to present in Darabricks:

- Databricks Serverless SQL
- Databricks AI/BI genie (chatbot answering question about your data)
- Photon performance
- Databricks Lakeflow integration
- Rag application on Databricks

The content should depend if it's for technical audience or business users.