We usually use 你要努力工作 but not 你要辛苦工作, for it's impolite and has a meaning of forcing others to work, which might make others feel bad.

我要_______ 工作。We usually fill the blank with "attitude " word , just like “认真”(work hard). “辛苦” is not the 'attitude' , it is a feeling ，so we don;t say "我要辛苦地工作"，we can say “我要认真\努力工作。”

在中国，我们一般说“你要努力的工作”