I think there's a very simple reason why you haven't found anything about his service during WW2 - his service record has not yet been made public. Apart from a small handful of REME personnel and a few of the the smaller Corps, the process of indexing and releasing the records of those who served between 1920 and 1963 has only relatively recently begun at TNA, with Ancestry undertaking the digitisation of the records. The main official records which we do have from WW2 are the casualty reports which name men who were reported missing, captured or killed. Since you haven't found Albert Coley among them, it suggests that none of these things happened to him.
Furthermore, under TNA's current rules Albert's record won't be released for some years yet as he was born less than 115 years ago.