Sharing individual calendar(s) to a group

We are running Office 365 (E3).

I have a request where 5 users can share/show their individual calendar to each other or a shared calendar let's say 'Sales Team'.

The idea is that they don't have to manually add appointments - just whatever they have in their calendar to show up either to this shared Calendar or preferably shows up in everyone's own ('My Calendar') - guess they can have different color for different people to help them identify.

Is it possible? What is the best option?

Any help will be appreciated.

Thanks,

Ashok

am7777