Yes, people with the Cayley surname feature in fiction. They include a murderer in A A Milne’s only crime novel, an intrepid late Victorian female in a romp by Grant Allen, and a Lady Sarah Cayley in a novel by May Sinclair. I have added a page to the website listing works I know of. Please tell me of others you come across, using the contact page.
Several of the novels are available for free download on the internet, from sites like http://manybooks.net.