A person I used to work with sent me a LINE message to say he/she would like to get together because we haven't seen each other for a long time.
ーA person I used to work with sent me a LINE message to say he/she would like to get together since we haven't seen each other for a long time.
「元同僚が久しぶりに会いたいとラインを送ってきた」
a person I used to work with で「元同僚」
to get together で「会う」
「元同僚」は
former co-worker
old co-worker
のようにも言えます。
ご参考まで！
カナダ 
