I was going to tell you it's easy, you just scan the horizon, climb something tall if you need to, look for the red heart, done... but that was for non-dusty years. This year if visibility is lower it may take some resourcefulness. Just ask people if they've seen it, and if you have a bike, pedal around. They move around but they are not exactly trying to hide, and if you patrol the region between 10:00, 2:00, and the Temple, you'll probably spot them before too long. Though of course it will tend to pop up next to you before you realize you want to go looking for it, and then on the one night you desperately want to find it, it will be nowhere to be found. That's kind of how things tend to work.
Finding the diner, now that's a challenge. I wish THEY would leave a trail of balloons. (anyone know if they're coming back this year?)