Not trying to come off trite, but the RFC [0] has a simple ASCII diagram of the message flow and the structures that follow are fairly easy to read. Granted you have to hop to a couple of other RFCs to understand extensions and maybe even real world impls to understand some changes (e.g. no time in the random block of client hello), but it's worth perusing if you're interested.
I think they mean a side-by-side ASCII interpretation like that supplied by `hexdump -C` - where any alphanumeric character is printed as itself and every other character is printed as a "."
I was afraid that it wouldn't fit and might be overly complex for what was gained (there's not much text in there). However there's a PCAP at https://github.com/syncsynchalt/illustrated-tls/tree/master/... if you'd like to load it up in wireshark or tcpdump.
