Albert Camus - Living Without Appeal

Presently I'm reading my way through the literary legacy of Camus. In re-reading "The Myth of Sisyphus" I have been particularly struck by his idea of living without appeal - to various religious and secular "leaps of faith" to save us from the ambiguity, inscutability, irony and absurdity of the human condition. What does it mean to live "by appeal" to a higher power of greater purpose - whether religious or secular? What does it mean to live "without appeal" to any transcendent or immanent purpose other than an ironic passionate indifference in the midst of a meaningless and absurd universe? Why is Camus not an existentialist or a nihilist, as he insists? Any thoughts? How do you play it?