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