The strum pattern changes from chorus pre-chorus etc. But the main thing is a synco-pated rhythm. Meaning you play off the beat or upbeats.
It would be D D* U D U
*Pause a bit so you end up playing U D U on up beats
Hard to explain but its all up to you your cover your pattern. Chorus is just D D X X X and yeah. Watch the music vid on youtube it helps too he made a tutorial. Hope this helps