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