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