tweak the printing of FPGroup

src/types.jl

@@ -264,10 +264,18 @@ function FPGroup(
 end
 
 function Base.show(io::IO, ::MIME"text/plain", G::FPGroup)
-    print(io, "Finitely presented group generated by:\n\t{")
-    Base.print_array(io, permutedims(gens(G)))
-    println(io, " },")
-    println(io, "subject to relations:")
+    println(
+        io,
+        "Finitely presented group generated by $(ngens(G)) element",
+        ngens(G) > 1 ? 's' : "",
+        ": ",
+    )
+    join(io, gens(G), ", ", ", and ")
+    println(
+        io,
+        "\n    subject to relation",
+        length(relations(G)) > 1 ? 's' : "",
+    )
     return Base.print_array(io, relations(G))
 end