alternatives for "guy"

the people is commonly used in our workplace.

Call up the people in [department name].

Someone is also used

Can you get someone in accounting to take a look at this?

Or, it's just omitted if it's a whole team:

Can you get Finance in here right now?

EDIT: I should add that if a team is all young men, sometimes the term boys is used, though this is usually used within a team and is much more casual.

E.g. The IT(sub-dept.) Manager might say to others in the IS(main dept.) team: "The boys are out fixing a problem, they'll join us shortly"

It is very normal in English speaking workplaces. I think for day to day interactions with coworkers "guy" is appropriate, but in a more formal setting something like someone, person/people, or gentleman/men (when applicable) might be better. And as Rhodri said, there is then the issue of women being "guys." I worked with an organization that had a strict policy against using the term "guys" in order to be gender sensitive. I didn't realize how often I used the word until my work with them!