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