Permutation diagram is confusing

[lvh]

@lgarron mentioned in #80:

Page 35 [diagram]
This is actually quite a nice diagram, but also a bit confusing if you don't already know what's going on. The E_k arrow feels a bit misplaced, and the diagram implicitly suggests that every permutation is a single-cycle derangement.

Here's a screenshot of the diagrams in question:

Two points:

• The diagram definitely incorrectly implies that all random permutations are one big cycle. I seem to remember that for a random permutation of $n$ elements, you'd expect to see about log n cycles. I'm guessing that just adding one cycle would be fine.
• Regarding the E_k arrow, that's how I've always seen a relation written down in visualized sets like these. Maybe the spacing could be a bit better? I'm open to hearing about alternatives, but I do want the illustration to make it clear that this is what happens when you go from one point to another by encrypting under the given key; that's also very important in order to understand the second diagram.