Control flow graph using switch case

I tried to do control flow graph for this coding (White box testing)

#include<stdio.h> 
int main() 
{ 
int choice; 
printf("Enter your choice(Enter -99 to exit): ");
scanf("%d",&choice);
while(choice != -99) { 
    switch(choice) { 
        case 1: 
          printf("Green\n");
          break;
        case 2: 
          printf("Orange\n");
          break;
       case -1: 
          printf("Bye\n");
          break;
       default: 
         printf("Invalid option\n");
       }
   printf("Enter your choice: ");
   scanf("%d",&choice); }
   return 0; 
}

This is the answer I so far tried

I don't know weather this is correct or not. I tried to do the rest of it.But I couldn't do. I tried and search so many times, but no satisfied answers are there. Please tell how to do it correctly.

I did questions using if else but not complex questions. This is not my homework question. Just trying to get knowledge using switch case..