sensord is an rrd-based logger for lm_sensors

Sensord is a daemon that can be used to periodically log sensor
       readings from hardware health-monitoring chips to syslog(3) or
       a round- robin database (RRD) and to alert when a sensor alarm
       is signalled; for example, if a fan fails, a temperature limit
       is exceeded, etc.

A classic redhat-style initscript is shipped in the doc directory,

A command similar to this one would log sensor data into a file under
/var/log:

/usr/sbin/sensord -i1m -l30m -1 -t3m -r/var/log/sensord.rrd -d -a

Viewing the graph requires a bit of rrdtool mastery, but
man sensord suggest an option to generate a cgi script to be
used by rrdcgi and delivered through a CGI-supporting web server.

Nginx (not shipped with Slackware, but popular) does not support
CGI, so you may have to delve into fcgiwrap and/or spawn-fcgi.