I tackle this with a two stage approach - graphical appearance and simulation behaviour
For graphical appearance you should create a custom component with the correct number of terminations and set up custom graphics to precisely define the appearance - put the graphics on a separate layer so you can turn them on/off easily
For simulation behaviour you will need to place a regular relay and connnect it to the pins of the custom component. Then use logic links for each extra set of contacts. Set the Logic so that when the input to the coil is low then one termination is high and when the input to the coil is high the other termination is high.
Here's a simple example showing the simulation internals