There is a turnout and parking area at Siesta Lake. From the parking area there is also a well-worn trail along the south side of the lake (see A on the map). Walking along the shoreline of this lake gives you different perspectives of the lake and many nice views. I usually look for an area with an interesting foreground, whether it is a fallen tree or a particular interesting group of reeds.
The best location from which to photograph Siesta Lake: (A) the southern shore of the lake.