Scatterplot axis labels

Hello,

I have a chart comparing performance of several medical groups (attached). It is a modified scatterplot where each point represents a score for a particular medical group. The scores are plotted along the horizontal axis, and the groups are shown along the vertical axis. They are currently labeled as 1, 2, 3, etc., but I want the axis labels to read Grop A, Group B, Group C, etc. How can I do this?

Thank you very much in advance.