One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(5,6,8,10)(7,9,11,12)(14,17)(15,19)(5,6,8,10)(7,9,11,12)(13,14)(15,20)(16,17)(18,19)(22,25)(26,28)(5,6)(7,9)(8,10)(11,12)(13,14,16,17)(15,18,19,20)(21,22)(23,26)(24,25)(27,28)(1,2)(3,4)(5,6)(7,9)(8,10)(11,12)(13,15)(14,18)(16,19)(17,20) involution — undirected(5,7,8,11)(6,9,10,12)(13,14)(15,18)(16,17)(19,20)(21,23,24,27)(22,26,25,28)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.