Hi there,
And Welcome Here. There is a schematic available in the WiKi give that a peek also, but the S3 uses the B2B connector for the SX1262 so the other pins are still available, I connected the external buzzer and the I2C ssd_1306 Display in the picture above. The Radio is connected with the SPI interface for example on the Nrf52840 Version So less or No pins are available. The ESP32S3 has more flexibility for that.
Check it out, 
XIAO ESP32-S3&Wio SX1262 Kit | Seeed Studio Wiki
HTH
GL 
PJ 