The incident happened on Newfoundland Road on March 17 at 9pm.
The offender met the victim on Stapleton Road before they walked towards the bridge on Newfoundland Road, where he then attacked her.
Officers are asking for the public’s help in identifying the man.
He is pictured wearing a snake-style ring on his finger, a black coat and a black hat with a logo on the front.
Detective Constable Paul Sell said: "We are doing our utmost to support the victim through this difficult time. She has shown great strength through the investigation, and we hope this appeal will bring us a step closer to giving the victim closure.
"We are now appealing to the public to help us in our investigation. We believe the man in the CCTV image can help aid our enquiries and would like anyone with information to come forward."
If you can identify the man in the CCTV or witnessed something, call 101 and quote reference number 5222068041.