Correlation network representation
When plotting networks where only the weight of an edge is known like this one. The relative position between elements of the networks is irrelevant. The only informative part of the graph is (usually) the size of the edges, where is the thicker means more weight. This isn't a PCA, so the distance between different nodes is not relevant. 

For those reasons there are several methods to build these networks, some of them give more emphasis to represent better the degree of the network or other characteristics of the networks. 



I consider this representations bad for informing about the networks, because the cut off is arbitrary and the distance between nodes is not informative. One could first do a PCA or MDS and then add the edges between the nodes, this way the relative distance between the nodes would be meaningful as well as the edges. Or one could also use a heatmap to represent all the correlations between the nodes.