If I phone a hotel, for example, and I ask for "Mr Smith in Room 302", the receptionist would try to call him in Room 302. About 50 years ago, that receptionist would have waited until she could hear his phone ringing and would then say to me "It's ringing for you". What she means is "On your behalf, as requested, I have made his telephone ring". I would then hear the ringing tone too and Mr Smith would either answer or not answer depending on whether or not he was in his room.
I haven't heard the phrase "It's ringing for you" for many years and I very much doubt it's in use now.
How old was the book you were using?
I can't make a case at all for "It's calling for you". That makes no sense.