One vertex per element, one color per generator, with an edge from x to x·s.
(6,10)(7,8)(13,14)(15,16)(17,18)(19,20)(22,25)(26,27) involution — undirected(2,4)(5,6)(7,12)(8,11)(9,10)(13,15,19,18)(14,17,20,16)(21,22)(23,26)(24,25)(27,28)(1,2)(3,4)(5,7,9,8)(6,11,10,12)(13,16,19,17)(14,15,20,18)(21,22)(23,26)(24,25)(27,28)(5,8,9,7)(6,11,10,12)(13,17,19,16)(14,15,20,18)(21,23,24,28)(22,26,25,27)(5,6)(7,11)(8,12)(9,10)(13,18,19,15)(14,17,20,16)(21,22)(23,27)(24,25)(26,28)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.