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