To interface your own board with the MAX17055 GUI, you will need the DS91230 I2C to USB adaptor. On the I2C side interface, we use a standard RJ11 connector. The pinout is shown on MAX17055 EVKIT schematics:
J9 is the standard RJ11 PCB board connector. Four lines (ALRT,SDA,SCL,GND) should connect to the RJ11 connector.
Using this schematic, you can utilize the Maxim GUI as a tool for quick testing on your custom design.