The cache is not at the listed coordinates.
Many years ago the Yoothamurra Kiosk was a thriving business catering for travelers going to or from Wisemans Ferry. Alas nowadays it is completely abandoned, and lies derelict and covered in graffiti. There are signs up and down the Old Northern Rd promising a coffee stop, but I have never seen it.
The Old Northern Road and Wisemans Ferry deserves more geocaches, so here is my first offering, hopefully of many.
The cache can be found at S33 31.ABC E151 01.DEC where:
A = the digit that appears the most times in the kiosk's phone number
B = the second digit of the street address
C = the number of Coca Cola signs cubed
D = the third digit of the street address number
E = the third digit of the full phone number