In my opinion if the internet is a collection of redundant high speed wide area links. Than it is using Star topology.
lets take an example think about a wide area network the one which is provided by the local ISP(internet service provider) so their are many local ISP's which provides the internet facility.(we can see them as a high speed wide area networks)
All those local ISP's are also connected in the star topology and are serviced by national ISP's like MTNL, reliance etc.
Like this the hierarchy goes on and on and every computer is connected with each other.