Categories of visa

1) South Sudanese Nationals in Swiss:

South Sudanese nationals who are traveling with a swiss travel document or a swiss passport requires a visa and must fulfill all the ncecessary required procedures. 
South Sudanese nationals who possess south sudanese passports do not need a visa to travel to south sudan.

2) Swiss National and other EU national:

Swiss nationals must fulfill all the visa requirements to obtain a visa. 
Other EU nationals applying in geneva must have a valid permit that proves he is base or having business in 
geneva, otherwise they have to apply from their respective South Sudan, missions in their country.
This applies to all others non swiss nationals.