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