Upvote:6
Trying to take the entire park in with just one day will be a lot of driving (300+ miles) and not a lot of time for sightseeing. I would concentrate on the lower loop and work in some variety.
Stop at Old Faithful and Midway Geyser Basins to stroll around a bit. Both are fairly level with a variety of different thermal features, geysers, hot spring pools. If timing is in your favor, there are a number of geysers that you may witness erupting.
As you work your way towards Madison, there are often elk or bison in the meadows along the road (and likewise when you work your way down the east side as well).
At Norris cut across to Grand Canyon area and take in a couple of the vistas overlooking the canyon and also overlooking the Upper & Lower Waterfalls.
Like I mentioned above you will likely see lots of bison as you head down through Hayden Valley. Perhaps taking a break at Mud Volcano to check out the unique thermal mud pools there.
At Lake be sure to drive up to Lake Butte Overlook, a few miles past Fishing Bridge as you head for Cody. Gotta keep a sharp lookout as the turn is not well signposted.