This sonata is a favourite of mine. I listened to it many, many years ago during an encore in Milano, but I was unable to get a score of it—I had a clear recall of the cadenza, but thematic indices do not include cadenze. Then, years after, during a month spent in Sydney as part of my Ph.D. studies I was hosted by a family with a piano and some old scores, including a book containing twelve Scarlatti's sonate… you can imagine my surprise when during a sight-reading I found back my old love!
The sonata is all about rhythm—it has a strongly syncopated design. The cadenza, in particular, is astounding. Here's the score (Lilypond sources).
Thanks to Lilypond's MIDI output capabilities, you can even get a MIDI file of this sonata, or (courtesy of Timidity) an Ogg Vorbis digital audio rendition (harpsichord ♩♫; piano ♩♫; organ ♩♫; concertina ♩♫; marimba ♩♫).