Parramatta Eels Cayless started his career in the
National Rugby League with the
Parramatta Eels alongside his older brother,
Nathan Cayless, who had already been with the club for three years. In 2001 he made his representative début for
New South Wales Country Origin.
Sydney Roosters The following year Cayless moved to the
Sydney Roosters and played for them at prop forward in their
2002 NRL Grand Final win over the
New Zealand Warriors. Having won the
2002 NRL Premiership, the Roosters traveled to England to play the
2003 World Club Challenge against
Super League champions,
St Helens. Cayless played at prop forward in Sydney's victory. He played at prop for the Sydney Roosters in the
2003 NRL grand final which was lost to the
Penrith Panthers. Cayless played for the Roosters at prop forward in their
2004 NRL grand final loss to cross-Sydney rivals, the
Bulldogs.
St Helens Cayless played for St Helens as a prop forward in their
2006 Challenge Cup Final victory against the
Huddersfield Giants. St Helens reached the
2006 Super League Grand final to be contested against
Hull F.C. and Cayless played as a prop forward in Saints' 26–4 victory. As 2006 Super League champions, St Helens faced 2006 NRL Premiers the
Brisbane Broncos in the
2007 World Club Challenge. Cayless played at prop forward in the Saints' 18–14 victory.
Wests Tigers After spending four seasons in the
Super League, in October 2009 Cayless signed with the
Wests Tigers on a two-year contract starting in 2010. He started the first three games of the season from the bench, but injuries saw him make no further appearances for the Tigers in 2010. He announced his retirement before the start of the 2011 season. ==International career==