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