You're the senior around this place, so please do also think about nurturing the juniors.
As a senior, it's your responsibility to not just think about yourself, but also about nurturing the juniors.
「ベテラン、先輩」→「Senior」
「後輩」→「Junior」
「育成する」→「To nurture」
「責任」→「Responsibility」
優しい言い方:
「You're the senior around this place, so please do also think about nurturing the juniors.」
「あなたは先輩なので、後輩の育成も考えるようにしてください」
厳しい言い方:
「As a senior, it's your responsibility to not just think about yourself, but also about nurturing the juniors.」
「あなたは先輩として、自分のことだけでなく後輩の育成を考えるのもあなたの責任だよ」