First and foremost, communicate this to him very openly and lovingly... without it coming off as pressure (since he's already working a full day). But he probably doesn't have a genuine understanding of how much you miss him and need him, and if he did he might start to focus more on how you guys can make more time for each other.
You need to be a little creative here... try and think of windows of opportunity. For example, how far away does he work? Is he close enough where you can meet him for lunch breaks? Not only will that allow you two to connect mid-day, but it can also be an opportunity for some excitement if you wanted to have a sexy rendezvous as well... could really spice things up for you guys.
I also suggest you both read the book His Needs, Her Needs
– it is a fantastic reading about the give and take in relationships and since you're both young it is a perfect time to get a good understanding of how to make your future work together, because it's a very long road ahead. This book will seriously help secure your future together if you take it seriously and live by it.