Sisyphus
Sisyphus is the symbol of modern man, capable of attaining consciousness that his existence is absurd. More than that awareness of this fact, he can also find meaning in his life precisely by accepting the absurdity. In this way, Sisyphus the symbolic incarnation of modern man suffering from an existential crisis who looks to the absurdity of life as a means of salvation.
The Punishmet
The infamous punishment to which Sisyphus has been sentenced is quite literally a job that successfully be done. As a symbol, this element of the punishment is fairly weak. Camus lends the punishment philosophical depth by virtue of how he imagines Sisyphus comes to deal with the true nature of the punishment: with an eternal sentence of doing completing a job that can never done, Sisyphus not only must perpetually keep trying, but also realize that he cannot even hope for success. Facing this knowledge of eternally recurring lack of success by admitting there is no hope is what actually finally allows him to find happiness merely in the doing. The punishment is a multi-layered symbol covering impossible tasks, loss of hope (also known as existential dread) and, finally, giving his life meaning.
The Boulder
Tough, solid, enormous, impenetrable and immutable, the rock that Sisyphus must continually push seems to be eternally the victor in his struggle to push it over the top. And yet, his happiness at finding meaning in the struggle means he is the victor, suggesting the symbolic power of the mind to defeat any obstacle.
Water
Water is such a blessing to Sisyphus that it is the mechanism by which he commences upon the path to eternal damnation. He is willing trade vital information for water and this dooms him. Little surprise then that when Sisyphus makes a short term deal to return to the earthly domain, the presence of water sorely missing from the underworld is one of the aspects that urges him to break the deal and fail to return. Water is thus the primary symbol of life; it is everything that makes living worthwhile.
The Transgressions of Sisyphus
The specific reasons for Sisyphus being punished is ambiguous, but the myriad legends all have one thing in common: Sisyphus was a mortal who compelled to disrespect the gods. He steals their greatest secrets, he temporarily ends death on earth and he rats out Jupiter. The utter lack of respect for and total scorn toward the gods that are represented as the true nature of his character, make him a perfect symbolic figure for existentialism and its rejection of the need to find meaning for one’s existence through the mediation of religious figures.