So firstly, the first two columns in the periodic table are classed as the 's' group, the next 10 groups/columns, which are the transition metals are called the 'd' group, the last 6 colums are classified as the 'p' group. Also the s group can only have a maximum number of 2, the p group with 6 and d group with 10.
Locate Sulphur on the periodic table and it is on the right hand side of the periodic table, so it is in the 'p' group, this means that its last electron is in a p orbital. Starting from the top, label the row 1-5 starting from Lithium and should notice that Sulphur is on the 3rd row. This tells us that the electronic configuration will end on a 3p orbital. By observing the 3nd row, can now count from Sodium to Sulfur, with Sodium having a 3s1, Mg-3s2, Aluminum 3p1, continuing to Sulfur which is 3p4.
So can now conclude Sulfur's configuration ends in 3p4. By adding the previous configuration, Sulfur will be 1s2,2s2 2p6, 3s2,3p4.