The transaction appears to have a very low "fee per byte" of 20.09 satoshis per byte. A transaction I just completed got confirmed 5 times within 30 minutes or so with a fee per byte of 298 satoshis/byte.

You need to make sure the fee you specify for the transaction is attractive to miners, otherwise it will take a long time for the transaction to be confirmed.

Earn.com has a great bitcoin fee tool at https://bitcoinfees.earn.com/ (I'm not associated with Earn in any way)