I have heard a few FIFO and travelling dads say that their kids think they work at the airport. Mum is always dropping him off there and that is where we pick him up from.
How about taking a few photos of your workplace, your room and the cafeteria on site (if you work away from home), of the city you are visiting (if travelling for work), or even of your home (if you live apart from your children), and share them when you see your children. This will give your children a sense of where you go when you are away from them. The younger the children the more effective pictures tend to be.