Sensuous and sensual are close in meaning but not identical, and sensuous was actually coined by the poet John Milton so that he wouldn't have to use sensual. Sensuous usually implies pleasing of the senses by art or similar means; great music, for example, can be a source of sensuous delight. Sensual, on the other hand, usually describes gratification of the senses or physical appetites as an end in itself; thus we often think (perhaps unfairly) of wealthy Romans leading lives devoted to sensual pleasure. You can see why the Puritan Milton might have wanted another word.