In the decade before Mayo's migration to Australia in 1953, she held teaching positions at St. Martin's School of Art and Sir John Cass College in London. She became a member of the Society of Wood Engravers, and wrote and illustrated a series of books. She also exhibited at the Royal Academy and with the Royal Society of British Artists.
On arrival in Australia, Mayo became one of the many migrants who contributed to the postwar print revival. She taught at the National Art School in Sydney and was a member of Sydney Printmakers. Her career in Australia included working on murals and designing tapestries and posters. She designed the platypus for the one-shilling stamp, and in 1962 she was awarded the Vizard-Wholohan Prize for prints.
Mayo exhibited regularly in Australia until her emigration to New Zealand, where she taught at the University of Canterbury.