Wolves' 100% start to the campaign was brought to an end as the Bluebirds - who have now won four from four in the league - claimed a 2-1 victory at Molineux.
Joe Ralls put the visitors ahead only for Leo Bonatini to equalise, but former Wolves academy graduate Nathanial Mendez-Laing netted what turned out to be the winner for Cardiff on 77 minutes.
Afterwards, Coady said: "It's deflating. Whenever you get beat it's deflating, but it isn't nice to lose the first one of the season. They're a good team - they're not top of the league for no reason - but I feel like we let them dictate how we played at times today. We went away from how we want to play.
"We all knew how they were going to play - we knew they were going to make it physical and be horrible to play against. They did a good job of what they were doing, but I just think we needed to be a bit calmer on the ball and play how we play. We got sucked into how they were trying to do things at times, and we need to stop that.
"We needed to keep playing our football and concentrate on ourselves, and we didn't do that enough today.
"We're disappointed with the goals we let in. It's not nice to concede goals at home and we pride ourselves on keeping clean sheets, but it's now about learning and looking back on where we went wrong."
Wolves now face two away trips in a week - first to Southampton for their second-round Carabao Cup tie on Wednesday evening, before a return to league action at Brentford on Saturday ahead of the first international break of the season.
Coady says that the way his side now react to the Cardiff defeat will be a marker of how far they have progressed under Nuno.
"We were never going to go throug the full season unbeaten," he said. "It's about how we react and go again. In previous seasons we've not been good enough at that - we've tailed off and then gone two, three, four or five games without getting a win.
"It'll show how good a team we are if we can get back on it straight away.
"We've not become a bad team overnight - we're still a good side and we still know how to play. We move on now - we've got the crowd behind us and we all know what we want ot do. If we want to do anything this year we need to show how good we are now."