The interpretation of the estimated coefficients depends on: the link function, reference event for the response, and reference levels for the predictor. The estimated coefficient associated with a predictor (factor or covariate) represents the change in the link function for each unit change in the predictor, assuming all other predictors are held constant. A unit change in a factor refers to a comparison of a factor level to the reference factor level.
To change how you view the estimated coefficients, you can change the event or reference levels in the Options subdialog box. For example, if your response was coded Low, Medium, and High, the default reference event would be Medium because it is last in alphabetical order. In most cases, using High as the reference event would make the results more meaningful.