You have four groups:
1. Change description to Group
2. Select Number of Shifts 4 in dropdown list.
3. Change Shifts in each box to get 1-2-3 and 4. Double-click to change color.
4. Change length of cycle to 8-days.
Start Date is optional.
5. In the calendar area, change the group in each day box to match your own schedule.
Make the calendar match your schedule, that's it. Press OK. Your calendar will be saved to the list of schedules.