This paper introduces NLDS-QL, a translator of data science questions expressed in natural language (NL) into data science queries on graph databases. Our translator is based on a simplified NL described by a grammar that specifies sentences combining keywords to refer to operations on graphs with the vocabulary of the graph schema. The demonstration proposed in this paper shows NLDS-QL in action within a scenario to explore and analyse a graph base on patient diagnoses generated with the open-source Synthea.