Hey there.
You want to go through site.Taxonomies
. It will list all taxonomies. Key is the taxononomy name, value is a slice of terms.
so on your page single.html you should:
{{ range $taxonomy, $terms := site.Taxonomies }}
{{ with index $.Params $taxonomy }}
<h2>{{ $taxonomy | humanize }}</h2>
{{ range . }}
[... build your term's link here]
{{ end }}
{{ end }}
{{ end }}
This has not been tested. Might need some tweaking if it fails at first try but you get the gist.
Cheers.