Transactions motive. Money is a medium of exchange, and people hold money to buy stuff. So as income rises, people have more transactions and people will hold more money
Precautionary motive. People hold money for emergencies (cash for a tow truck, savings for unexpected job loss). Since this also depends on the amount of transactions people expect to make, money demand is again expected to rise with income.
Speculative motive. Money is also a way for people to store wealth. Keynes assumed that people stored wealth with either money or bonds. When interest rates are high, rate would then be expected to fall and bond prices would be expected to rise. So bonds are more attractive than money when interest rates are high. When interest rates are low, they then would be expected to rise in the future and thus bond prices would be expected to fall. So money is more attractive than bonds when interest rates are low. So under the speculative motive, money demand is negatively related to the interest rate. (We have seen this already in chapter 5).