The Gailey Fiveways is a very confusing intersection in Taringa where streets come from many directions into a roundabout. It lends its name to the nearby Gailey Fiveways Shopping Centre.
The coordinates given are those of a bus stop that is somewhere near the actual Gailey Fiveways geocache. You will need to solve the puzzle below to find that actual coordinates. This map of the Gailey Fiveways roundabout area will be helpful for solving the puzzle.

The coordinates = S 27 29.abc E 152 59.xyz
d = the number of letters in Gailey
e = the number of letters in Fiveways
f = the number of roads coming into the Fiveways roundabout roughly from the west
g = the number of roads coming into the Fiveways roundabout from the north.
a = e + g x = d - f
b = f y = e - d - f
c = g z = e