After completing the truth table, write equations for each output segment. You should have seven separate equations for Sa through Sg. You may find that in the truth table there are much more 1s than 0s, so you may want to use Maxterms when you write down certain logical equations. Or, alternatively, you can try to complete truth table and write down equation for Sa through Sg, then add a not gate for each to get Sa through Sg.

Next, translate your equations to logic gates and sketch your design. You may use logic gates with any number of inputs. You may choose to optimize for design time or number of gates.