The woman was walking past Grafton Street, just off Clark Way, when her attacker allegedly struck, police said.
She is being supported by specialist officers.
Det Insp Andrew Day said: “We take reports of sexual offences very seriously and since the report was made to us we have carried out extensive and thorough enquiries.
“It is completely unacceptable to target anyone in this manner, and we are working tirelessly to find anyone who may recognise the man pictured.”
Police are also appealing for anyone who was in the area at the time, or anyone with dashcam or doorbell footage, to contact them.
