Collective decisions are everywhere: choosing central or local governments, selecting a candidate to hire for an open position, choosing a restaurant to share a dinner with some friends are examples of collective decision making situations. Social Choice provides a lot of methods which can help people making a decision in such situations. However, the diversity of these voting procedures and the mathematical background necessary to understand them can be seen as obstacles to the use of these methods in everyday situations by laypersons. We claim that information visualization techniques can help a lot the democratization of social choice, by providing people with some easily interpretable information and, in the end, helping them making informed collective decisions. In this paper, we present the Edge-Compressed Majority Graph, a technique dedicated to the visualization of the majority graph of a preference profile. Using an insight-based evaluation method, we show that this technique gives better results in conveying information about the preferences than other classical visualization techniques.