The 8 pointed star of khaos magick represents the different 8 different branches of khaos magick. This symbol comes from Michael Moorcock's eternal champions series. Variations of 8 pointed stars have appeared throughout history eg the star of Ishtar/Venus and the wheel of the year, but alas they are not signs of chaos.
In Crowley's Thoth deck , the 8 of wands is represented with an 8 pointed star, Crowley said he saw this as energy scattering outwards at high velocity. Even though the Khaos star is representing the 8 branches of Khaos magick, i ten to agree with Crowley's view and also to me its a sign of transcendence and reaching out to all areas of the universe.
The 8 branches of khaos magick are War Magick, Thinking Magick, Sex Magick, Ego Magick, Love Magick, Wealth Magick, Death Magick and the 8th being Pure Magick, more on each of those later.
Blessed be LadyO