Your game progress is linked to your Facebook account. You have to enable Internet Connection and Log in Facebook to restore your game progress from our Cloud.
If you can't restore your game please try the following steps:
1 – Make sure your Internet connection is enabled and you have a stable signal (for example, you are not far from your modem if you are using Wi-Fi).
2 – Make sure the time on your device is set automatically.
Settings > General > Date & Time > Automatically (Enable it)
3 – Make sure your are not running out free space on your device.
4 – Swipe the game away as described here: https://support.apple.com/HT201330, open it again and see if it helps.