The peculiarities of unmanned vehicle application in the field of cargo transportation lead to the formulation of new problems for optimising cargo transportation plans, where several types of additional constraints and conditions must be taken into consideration simultaneously. The process of solving such problems requires considering and analysing numerous heterogeneous parameters, which is most effective when done interactively using visualisation techniques. We consider a problem involving the formation of heterogeneous cargo transportation plans using unmanned aerial vehicles, and propose an approach for constructing a visual model to support the interactive setting of problem parameters and to display optimisation results via a visual interface. This approach is based on the concept of visualisation metaphors, including spatial and representational metaphors. The structure and features of the metaphorical representation for different problem formulations and modelling stages are discussed.