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