Depends which operator, and it's usually a four day, or very close to it, roster. On some companies, Suindays are regarded as part of yur core week, on others they are covered by additional overtime working. Rest days do tend to get grouped together, and the concept of "long weekends" is popular. Expect to be working about 2/3 weekends, and batches of 5 - 7 shifts. Some outfits have a set rest day pattern, with a long weekend every third week, but that only works if Sundays are outside the working week.
I've worked a 5 day roster before in a non driving role but it was alright because the shifts were only 7 hours each. Also a lot of "middle" turns have to be included instead of late and early turns all the time, which is better for less fatigue