When anda make cinta anda involve feelings, LOVE, passion. When anda have sex anda just have sex, without tampilkan your feelings for the person, with no affection, with no sweet words atau whatever, that's just sex.
Well both are pretty much the same. Making cinta can be also be ciuman and caressing other than intercourse and it also can be others like oral sex and anal sex (especially for lesbian and homosexuals).