Depending on what is being optimized, particularly total length of the graph edges vs. length of paths between the points, a minimum spanning tree might be improved by

• upgrading it to a Steiner tree (not likely to improve the example much, but there can be substantial difference with large gaps between clusters)
• adding extra edges as "shortcuts" to improve the ratio between the distance and path length between any two points (the smaller the ratio, the more convoluted the path)

Connect main dots(common lines). As in your picture looks like lines together but fragmented.