Aside from tgv's correct point that this is implicitly a recipe for something that isn't useful as a visualization, I think even if we were able to distinguish 4B colors and make sense of each pixel -> color assignment ... the math isn't on your side. You responded to a statement about nobody consuming a graph of 100B nodes. Suppose we don't have any concept of edge weight, and an edge is either present or not, but edges are directed, then you have 100B^2 (i, j) pairs for potential edges, each of which is either present or not (i.e. 10^22 edges, each of which is a bit).

4,294,967,296^2,073,600 is very large but 2^(10^22) is much much larger