Juggl contains (currently) four different layout options. You can choose a layout from the buttons on the left of the toolbar:
In order, these are the following layouts:
Force directed layout: A standard force directed layout, where nodes push each other away and links try to keep nodes together. Juggl uses the Cola layout by default, but this can sometimes give weird vertical results. A more standard approach that is like Obsidians graph can be used from the settings under Extensions > Force Directed Layout.
Concentric: Puts all nodes in a circle, with the 'focused nodes' in the center. The focused nodes are the nodes around which we use the local mode, or expanded nodes.
Grid: A standard grid-like layout, similar to Roam Research.