------------英文句子----------

Both Staff of the Sales Department and Staff from the Sales Department are correct.

Please note that
1) 'staff ' itself is a plural noun. we cannot put an 's' after the word. Staff means a group of staff members. If we are talking about one particular person in the group, we can say 'a staff member'.

2) always say 'Sales Department' instead of 'Sale Department'. we can only use the word without 's' when we are saying something is 'on sale'.

staffs of sale department

staffs of sale department